Tool-steel retainer for percussive tools.



W. PRELLWITZ.

TOOL STEEL RETAINER FOR PEROUSSIVE TOOLS APPLICATION FILED JAN. 7, 1911.

1,000,036. Patented Aug. 8,1911.

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W. PRELLWITZ.

TOOL STEEL EET11INEB. FOR PBRGUSSIVE TOOLS. APPLICATION FILED JAN. 7, 1911.

1,000,036, Patented Aug. 8, 1911.

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WILLIAM PRELL-wrrz, or EASTON, PENNSYLVANIA, ASSIGNOR T INcT-ERs'oL L-RAND COMPANY; or NEW YORK, N. Y., 'A oonronarron' or NEW JERSEY.

TOOL-STEEL RETAINER FOR PERCUSSIVE'TOOLS.

Specification of Letters Patent.

Application filed January 7, 1911. Serial No. 601,436.

To all whom it may concern;

of Easton, in the county of Northampton and State of Pennsylvania, have invented a new and useful Improvement in Tool-Steel Retainers for Percussive Tools, of which the following is a specification.

This invention relates to tool steel re- ,tainersfor percussive tools, such, for instance, as hammer drills, and has for its .principal ob ect to provlde a tool steel retainer which may be readily brought into and out of its operative position for limithave a considerable elastic yielding moveparts shown in Fig. 1.

ment longitudinally so as to obviate the tendency'of the retainer to break under the blows of the tool steel.

A further object is to provide such a relationship between the retainer and the tool steel holder that the tendency of the retainer when in use, will be to stay in engagement with the tool steel rather than to be thrown out of engagement therewith when subjected to the blows of the tool steel.

In the accompanying drawings, Figure 1 represents the front portion of a hammer drill in side elevation with one form of my improved tool steel retainer applied thereto, the retainer being shown in its operative position. Fig. 2 is a top plan view of the Fig. 3 is a transverse section taken in the plane of the line AA of Fig. 1. Fig. t'is a transverse section taken in the plane of the line B-B of Fig. 1. Fig. 5 is a longitudinal central section taken in the plane of the line C0 of Fig. 3. Fig. 6 is a plan view of the tool steel retainer showing the arms in their normally contracted position in full lines and in their spread position in dotted lines. Fig. 7 represents the front portion of a hammer drill in side elevation with a moditied form of my improved tool steel retainer applied thereto. Fig. 8 is a top plan View of the same. Fig. 9 is a transverse section taken in the plane of the line D D of Fig. 7. Fig. 10 is a transverse section taken in the plane of the line F.ia of Fig.

7. Fig. 11 is a longitudinal central section taken H] the plane of the line FF of Fig. and Fig. 12 ]S a plan view of the retainer.

Patented Aug 8, 1911.

the arms being shown in their normally con- I tracted position in full lines and in their spread position in dotted lines.

The front head of the hammer drill cylinder is denoted by 1, the drill steel by 3 and the drill steel chuck by 4. The drill steel is provided with an abutment for co-acting with the drill steel retainer to limit the outward movement or the drill steel when it is not striking its work, which abutment in the present instance, is shown as an annular shoulder 5, formed integral with the steel, which shoulder also serves to limit the distance which the steel may be inserted into its chuck. The front head 1 of the drill cylinder is provided with a pair of lugs 6, T, projecting from the opposite sides of the lead at points offset from its longitudinal axis. To the front of these lugs 6 and 7, the front head 1 of the cylinder is provided with shallow recesses 8, 9, upon opposite sides of the front head, which recesses serve as seats tor-receiving the arms of the tool steel retainer and holding the retainer in its opcrative position against unintentional dis placement as will hereinafter appear. These recesses 8 and 9 may be offset from the longitudinal axis of the front head, as shown".

The drill steel retainer shown in Figs. 1 to (l inclusive, is formed from a single length of wire bent to form a yoke 10 at the outer ends of side arms 11, 12, the inner ends of which side arms are secured to the front head 1 by engaging the oppositely arranged lugs 6 and 7 thereon. To permit a sutlicient elasticity to the retainer in a longitudinal direction, whereby the retainer will yield under the impact of the drill, steel due to the abutment 4 striking the yoke 10, the side 6, so that the retainer may be applied to the I lugs 6 and 7 by spreading the arms out of their normal position over the ends of the lugs 6 and 7 The retainer is held normally in its operative position by fiorcing the arms 11 and 12 into the seats formed by the re-' cesses 8 and 9.

- 7 to 12 inclusive is quite similar to the one shown in Figs. 1 to 6 inclusive.

In theforms of drill steel retainer herein shown, it will be seen that a retainer is pro- 15 vided which may be readily removed from and replaced on the drill. Itwill also be seen that the retainer may be very readily swung into and out of its operative position, and when in its operative position, is held against unintentional displacement both by the seating of its side arms in the recesses 8 and 9, and also by securing the retainer at points offset from the longitudinal axis of the drill. It will also be seen that by the provision of the coils in the side arms of the retainer, the retainer ma have a sufficient longitudinal yielding ovement to obviate any tendency of the retainer to be broken by the impact 01 the drill steel when the drill steel is not strikin its'work.

' While I have shown and described this retainer-inconnection with a hammer drill,

it is to be understood that it could be used equally well in connection with tools of various other types without departing from the spirit and scope of my invention, the

gist of which is to provide a novel,'simple and inexpensive retainer for retaining a tool steel in position with respect to its holder when the steel is not striking its work.

What I claim is:-

l. A tool steel, its holder and atool steel retainer comprising a wire bent to form a yoke for embracing the steel and 'longitudinally yielding side arms secured to the holder. 1

2. 'A tool steel, its holder and a tool steel retainer comprising a wire bent to form a yokefor embracing the steel and side arms secured to the holder at points oflset from its longitudinal axis.

3. A tool steel, its holder having pairs of oppositely arranged lugs and recesses and a, tool steel retainer comprising a wire ben to form a yoke for embracing the steel and side arms secured to said lugs and arranged its operative position.

4. A tool steel, its holder and a tool steel,

retainer comprising a wire bent to form a yoke for embracin the steel and" side arms secured to the hol er, said side arms being provided with coils for permitting a substantially longitudinally yielding movement, of the retainer.

5. A tool steel, its holder and a tool steel retainer comprising a wire hent .-t0 form a yoke for embracing the steel (and side arms having their inner ends coiled and secured to the hoilder and means for holding the retainer in its operative position against unintentional displacement.

In testimony, that I claim the foregoing as my invention, I have signed my name in presence of two witnesses, this fourth dayof January 1911.

WILLIAM PRELLWITZ.

Witnesses:

F. GEORGE BARRY, HENRY C. THIEME. 

